Direct observation of ferroelectric domain formation by environmental scanning electron microscopy

The evolution of the ferroelectric domain pattern in donor-doped barium calcium titanate during heating and cooling across the Curie transition temperature was imaged by orientation contrast imaging using an environmental scanning electron microscope (ESEM) equipped with a heating stage. The vanishing of the ferroelectric domains above the transition temperature as well as their recurrence during cooling was observed. The domain pattern of the sample largely remained the same, confirming that domain orientation is determined by elastic energy conditions (clamping), which scarcely change within the investigated temperature range. In a few cases a change in the domain pattern of single grains was observed during heating and cooling.